If you give out enough Experience and set your world’s Default Delay low enough you may experience the problem where some enterprising player dumps all of their experience into Speed, potentially allowing them to reach a negative speed value. If this happens, the combat system breaks. To solve this problem increase Default Delay until their speed is 0. To prevent this problem, the maximum experience you should ever give is (n(n+1)(2n+1))/6 where n is Default Delay.